Switchboard for telephone-exchanges



(No Model.)

J; P. DAVIS. SWITGHBOARD FOR TELEPHONE EXCHANGES.

N0.559,366 j Patentedmaylag.

turen STATES ATENT union.

JOSEPH P. DAVIS, OF NEW YORK, N. Y., ASSIGNOR TO THE AMERICAN BELL TELEPHONE COMPANY, OF BOSTON, MASSACHUSETTS.

SWITCHBOARD FOR TELEPHONE-EXCHANGES.

SPECIFICATION forming part of Letters Patent No. 559,366, dated May 5, 1896.

Application filed August 10, 1895. Serial No. 558,820. (No model.)

7'0 @ZZ whom it may concern:

Beit known that I, J osnrn P. Davis, residing at New York, in the county of New York and State of New York, have invented certain Improvements in Switchboards for Telephone-Exchanges, of which the following is a specification.

My invention is a new organization of switchboards for telephone-exchanges, whose object is to permit the distribution of subscribers incoming calls among the different operators with the purpose of economizing in the operating force by keeping the operators uniformly and continually busy.

It consists in the combination, with a multiple switchboard of substantially the ordinary character, of a call-receiving or annunciator board at which all the subscribers calls are received and from which they are distributed in a uniform manner to the different operators at the multiple board for the completion of the connection with correspondent lines. Each telephone-line is brought to a spring-j ack or similar switch connection and to a suitable signal-indicating instrument at the call-receiving or annunciator board, and also to a line spring-jack or plug-socket on each section of the multiple switchboard; and a system of office trunk-lines is provided eX- tending from the annunciator-board to each of the sections of the multiple board, whereby calls received at the annunciator-board may be transferred to operators at the several sections of the multiple board and distributed equitably between them, so that the work at operators have on hand and is therefore ableA to distribute incoming calls among the different operators in an equalized or uniform manner, giving to each a fair share of the work.

The apparatus in my invention for permitting this mode of operation comprises, then, an annunciator-board wheren are located an tus is illustrated in the accompanying drawing. Five substations A, B, C, D, and E are represented, each connected by a telephoneline, the lines being designated l, 2, 3, 4L, and 5 respectively, with the switching apparatus at acentral station F. Line l, for example, is connected with a spring-j ack o r connection- `socket d and with an annunciator a2 on the annunciator-board f andwith spring-jacks d3, a4, and a5 upon the three sections f2, f3, and f4 of the multiple board. Trunk-lines 6 and 7 extend from the annunciator-board f to the section f2 of the multiple board, terminating in plugs h and h2, by means of which they may be placed in connection with the spring-jacks. Other trunk-lines S and 9 eX- tend from annunciator-board fte the multiple section f3 and still others lO and ll from the board f to the multiple section f4.

A call-signal from station A will be indicated by annunciator a2 at the annunciatorboard f. The switchman stationed at that board, observing this signal, will insert plug 7L of trunk-circuit 6 into the spring-jack c1, of that line, and then in any suitable manner will inform the operator at section f2 that connection has been made with trunk-line 6. The operator at that board is supposed to be equipped with the usual telephone and with keys for connecting it with the trunk-line, and by means of this she will obtain from subscriber at station A the order for the required connection-say with station B. She will then complete the connection by inserting terminal plug h2 of trunk-line G into the spring-jack b3 of line 2. Immediately succeeding the call from station A a call from station C may be received at annunciatorboard f. The switchman at that board is aware that operator at section f2 is in the act of completing a connection, and accordingly IOO will use the terminal plug h of trunk-'line 8 to effect connection with spring-j ack c. This connection will then be transferred to the operator at section f3 and will be completed there. Another call received at annunciatorboard f may be transferred to an operator at section f4 by means of trunk-line 10. Still another would be sent to the iirst operator at sectionf2 after sufficient time had been given for the completion of the iirst connection by that operator. By thus switching different calls for answering and attendance to the operators at the different sections of the multiple-board, having constantly in mind the business on hand for each of the operators, the switchman is enabled to equalize the work of the diierent operators. They may all thus be kept continuously and uniformly busy, in which condition, as is well known, they perform their work most efliciently and quickly.

It is to be understood that the office trunklines may be equipped with any of the wellknown devices for automatically transmitting` signals between the terminal stations of the trunk-lines-for example, that shown in Patent No. 507,988 of November 7, 1893, to Oro. A. Bell*and that suitable means for testing at any of the boards to determine whether the line-called for be already occupied should be furnished, as the test system illustrated in Patent No. 808,815 of November 18, 1881, to Milo G. Kellogg.

The insertion of plug 71J in a connectionsocket at board fwill thus be signalized at the terminal of the corresponding trunk-line at one of the multiple switchboards, so that oral communication between the switchman and the operators may be avoided. Likewise the removal of the plug h2 from a socket of a multiple switchboard in response to a signal for disconnection will be indicated to the switchman so that he may remove the corresponding plug h from the socket into which it is inserted.

I am aware that various organizations of switchboards have been constructed involving annunciator-boards for receiving` connections, switchboards equipped with apparatus for completing the connection, and office trunk-lines between the annunciator-board and the switchboards for transferring calls, as shown in Patent No. 392,403 of November 6, 1888, to Francis Blake; but I believe myself to be the iirst to provide apparatus for the specific purpose of permitting all incoming' calls to be received by one operator and by him distributed among different operators, each of whom may complete the connection with any line of the exchange system.

I claim as new and desire to secure by Iletters Patent- In combination, an annunciatorswitchboard containing a connection-socket and an annunciator for each telephone-line of the exchange, a multiple switchboard of several sections each having in it a terminal connection-socket of each line oi the exchange, and trunk-lines extending from the said annunciator-board to each section of the said multiple board, as described.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 5th day of August, 1895.

JOS. P. DAVIS. lVitnesses:

GEO. WILLIs PIERCE, FRANK C. LocKwooD. 

